class Session::IDL

def clear
  stdin.puts "retall"
  stdin.puts "printf, -2, '__clear__'"
  stdin.puts "printf, -1, '__clear__'"
  stdin.flush
  while((line = stderr.gets) and line !~ %r/__clear__/o)
    raise LicenseManagerError, line if line =~ %r/license\s*manager/io
  end
  while((line = stdout.gets) and line !~ %r/__clear__/o)
    raise LicenseManagerError, line if line =~ %r/license\s*manager/io
  end
  self
end